Roosters Crow sounds sickly

My Rooster Max has always had a long winded crow. A week or so ago he started making a mild echo of his crow after he crowed as if he is sucking in breath after his crow making it sound as an echo. Today his crow is breaking up and sounds raspy. He is 5 months old now, is eating well, seems to lay around more than he used to though. Is he sick? Please help.

Take a listen to his lung sounds under a wing....listen for any wheezing, crackles etc... If so put him on Tylan 50 cattle injectable.
If no sounds, check the inside of his mouth for little red worms..called gap worm. Treatment is liquid Ivomectrian I believe.

If nothing then I'd be inclined to treat him with a little antibiotic anyway... Has he lost any weight? When was he last wormed?

I apologize but, I did not get your message last night when I made the last post. I only saw it now. We live out in the country and sometimes internet and phones do not always give us these things until later. No weight loss. Eating just fine. He is up and around quite a bit today but, today another rooster (Giggles) is making that sound when he crows. I will check in their mouth for worms, but, they were wormed in late June and again in July with Valbazen according to the directions given me on this site. Wormed the entire flock together. No hens were laying eggs at that time. After Giggles started making that sound today, I read some on here and started the flock on Duramycin-10 in case it is Infectious Synovitis or CRD. 1 tablespoon in a gallon of water. Should I give the 2 roosters injections of the med you listed instead? If so, where do I get this medication injection? If you suggest continuing with the Duramycin-10, do I need to throw away eggs during this treatment of antibiotics?

Thank you so much for your reply and the other reply I got. Any and all advise is greatly appreciated.

Okay. We just went out and listened to lungs in Max and others, all sound the same; no crackling or wheezing. Just breathing in and out. Checked in mouth, no worms. I'll wait until you read my other response and reply before I do anything else.

You can keep them on that..its not very strong so it shouldn't hurt. I wouldn't do any other med unless things worsen. If so id stop the one and go to Tylan. You can find it at TSC and some restores. In the cattle medication.